The present invention relates to a bicycle component having a hub shell for a wheel of an at least partially muscle-powered bicycle and to an adapter unit for a hub of an at least partially muscle-powered bicycle and a two-wheeled vehicle comprising a frame, a fork, and an at least partially muscle-powered drive. The bicycle component and the two-wheeled vehicle comprise at least one adapter unit for fixing the wheel of a two-wheeled vehicle to the dropouts.
In the prior art, a great variety of bicycles have been disclosed whose wheels are attached in a number of ways to the dropouts or the fork or the frame of the bicycle or the two-wheeled vehicle. For example quick releases are usually used where as a rule the hub of a wheel comprises a hollow hub axle through which a quick release is passed for fastening to allow fast demounting and re-mounting of the wheel as needed. Hubs for quick releases as a rule comprise a stationary axle whose axle stubs are pushed into the dropouts of the bicycle where they are fastened by means of the quick release. It has been shown that hubs having a large axle diameter provide for higher stability. For attaching these hubs whose stationary axes are larger in their inner diameter, adapter units are mounted onto the axle ends, the adapter units providing on their outside surface an axle stub having a smaller outer diameter so that these hub types can be received in conventional dropouts.
For a number of years, hubs for through axle systems have increasingly been employed, the through axle showing one threaded end which screws into an internal thread on the dropout of the fork or the frame. These through axles enable increased rigidity of the system.
All types of wheels of two-wheeled vehicles are increasingly used with disk brakes where the brake disk is non-rotatably connected with the hub shell. The “Centerlock” system by Shimano has emerged as a de facto standard where the outside surface of the hub shell is provided with a non-round disk accommodation to non-rotatably receive the brake disk. One end of the hub shell is provided with an internally threaded circumferential shoulder into which an attachment ring screws, a so-called Centerlock Lockring, to axially secure the brake disk. These standard brake disks and standard fixing rings show standard dimensions so that these brake disks can be mounted to hubs of different manufacturers.
The contact surface of the axle or the adapter unit with the dropout of a frame has been enlarged to increase the rigidity of the wheel accommodation. To allow attaching a fixing ring for example for a Centerlock brake disk to a preassembled hub, the maximum diameter of the adapter unit must therefore be smaller than the clear inner diameter of such a fixing ring. In the case of Centerlock brake disks, this means that the outer diameter of an adapter unit cannot be larger than slightly below 26 mm. If the outer diameter of the adapter unit were larger, then mounting the brake disk would involve to first demount the adapter unit, then mount the brake disk, attach the fixing ring and finally reattach the adapter unit. Such demounting and mounting steps are undesirable in series production since for one they cause work, and for another they considerably increase sources of error. If these hubs are incorrectly mounted then the bicycle manufacturers and possibly also of the hub manufacturers may have to face claims for damages due to product liability. Then the question arises whether the liable party is the bicycle manufacturer who first disassembles and then reassembles the hub for mounting the brake disk or else the hub manufacturer. Moreover, as was indicated, every additional step involves additional costs.
It is therefore the object of the present invention to provide a bicycle component with an adapter unit and a two-wheeled vehicle comprising such a bicycle component and an adapter unit which allow to overcome at least part of the drawbacks described above.